1. Technical Field
Exemplary embodiments of the present invention relate to a real-time service monitoring apparatus and method using a time stamp in a network node; and, more particularly, to a real-time service monitoring apparatus and method which uses a time stamp to measure a packet loss or latency in real time in a network equipment such as an Ethernet switch without an additional device, and provides the measurement result to monitor a real-time service such as Internet Protocol Television (IPTV) or video phone.
2. Description of Related Art
Conventional traffic monitoring technologies can measure the quality of a network service only in an end-to-end manner because of the characteristic of the network service. Furthermore, dedicated monitoring equipments are installed in the network to measure the quality of the service. For example, a service which is provided using a tap or the like can be monitored at a specific network node, if necessary.
In the conventional technologies, however, the dedicated monitoring equipment should be installed in a large number of equipments which are network nodes. Such an installation costs a great deal, and is almost impossible to implement. Therefore, it is almost impossible to accurately find where a problem occurred or which problem occurred, although the quality of a real-time service such as IPTV or Voice over Internal Protocol (VoIP) is degraded.
That is, various applied programs or protocols mounted in the internet service are designed by an end-to-end concept in the conventional technologies. Therefore, although a problem occurs in the service, only a terminal can recognize the problem. On the other hand, the network equipments in charge of transmission have a difficulty in grasping the state of the service.
Therefore, to monitor a real-time service on a network, systems configured to monitor the real time service should be installed on the network. However, since such monitoring systems cost a great deal, it is almost impossible to install the systems in every network equipment.
For example, a real-time service terminal supporting the real-time service can recognize whether a traffic problem such as packet loss, frame loss, delay, or jitter occurs or not. However, even the real-time service terminal cannot check at which equipment a problem occurred and which problem occurred. This may suggest that the traffic management of the network for the real-time service is not performed smoothly.
In the conventional technologies, a tap may be set in the network such that some flows are sampled to measure a packet loss, delay, a jitter and so on. However, since the quality of the service is analyzed statistically, it is impossible to directly analyze the service.
Therefore, the conventional real-time service monitoring technologies cannot directly measure the quality of the service across the entire path. If the conventional technologies are used to measure the service quality across the entire path, the cost may increase by geometric progression.
In other words, in the real-time service quality monitoring technology, an image quality is measured at a head-end stage, and sampling is used to measure the image quality at an edge stage. Furthermore, the image quality is measured at a terminal. However, a broadcasting server cannot sample and analyze whether a service is smoothly transmitted to a subscriber network or not, or grasp the state of the service in a Set Top Box (STB), and cannot acquire information on intermediate nodes.
Accordingly, a traffic monitoring server cannot find a network equipment in which a problem occurs on the network, and cannot check in real time which problem is occurring on the network. The network management for the real-time service is not performed smoothly.